


New Week, New Rules

by what_should_i_post_here



Category: Teenage Mutant Ninja Turtles - All Media Types
Genre: Anal Sex, Desk Sex, Foursome, M/M, Rimming, Turtlecest, tcest
Language: English
Status: Completed
Published: 2017-02-18
Updated: 2017-02-18
Packaged: 2018-09-25 07:49:14
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,407
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9809987
Author URL: https://archiveofourown.org/users/what_should_i_post_here/pseuds/what_should_i_post_here
Summary: After becoming intimate with each other, the brothers come up with a fair system to share each other equally. It seems not everyone's on board with it, though.





	

**Author's Note:**

> Honestly, this idea would have worked better as a chapter story, but as you may already know...I'm no good at those *awkward blush*
> 
> So please enjoy the poorly written smut

"Hey, Don," Leo called out as soon as he stepped into his brother's lab. As usual, Donnie was leaning over his desk working on some contraption.

He gave a slight nod in reply, too engrossed in his project to speak or give a wave back.

Whatever Leo had originally come in for was lost after watching Donnie's form spawled out in front of him in the most enticing way. The leader licked his lips carefully, trying to tone down the bulge that had begun to form below his belt.

"Was there something you needed?" Donnie asked, his eyes still focused on the project in front of him.

Leo quickly shook his head no and began walking further into the lab till he was directly behind his brother. He watched in fascination as his brother's tail had just peeked out of his shell and began wagging right in front of him.

Now this could have easily been from the excitement of him working on...whatever he was working on, but Leo found it almost teasing and couldn't stop himself from lunging forward.

He wrapped his arms around Donnie and carefully rubbed the bottom half of his plasteron against Donnie's ass. His brother's tail continued to move causing a delicious friction against the growing bulge inside Leo's shell.

Donnie chuckled and lifted the goggles he was wearing till they rested atop his head. "I knew you came in here for a reason."

"Want you," Leo mumbled into Donnie's carapace, too horny to form a complete sentence.

Donnie breathed out harshly. "You know we can't."

Leo pretended not to hear him as he began kissing up Donnie's shell till his lips met his shoulder. He pressed the flat of his tongue against the olive green skin and gently bit down.

Donnie's breath hitched and he found himself churring in response. "M-my week with Raph starts today."

It was an idea he and his brothers had come up with a little while after they all became intimate with each other. Master Splinter had caught on quickly and was completely understanding of it, but he had one rule: that what they did together did not affect them as a team.

It didn't take long before Leo and Raph, argumentatively the two alphas among the four brothers, began fighting over who got to be with who, when, and for how long.

Their father threatened to take away this new intimacy between them unless they came up with a better way to share each other.

That's when Donnie came up with the idea of them each being with another turtle for a week at a time, before switching off with another brother. And the system had worked well for a little while. But lately Leo had been feeling differently about their little set up.

For instance, on this particular day, Leo had eyes for no one but Donatello. Ever since he saw him during practice that morning, he wanted him.

Unfortunately, due to their little system, he wouldn't be with Donnie for another week. He had just ended his week with Raph, while Mikey and Donnie had just finished their week together.

Leo reasoned that Raph being his potential partner for the last week might have explained his current horny state. After all, on weeks where he was paired up with Raph, there was little to no sex at all. This was unfortunately because he and Raph were too stubborn to let one or the other bottom and often caused them to, if anything, simply bring themselves to completion, getting off to nothing but the noises of their other brothers together in another room.

Leo found himself growling possessively when Donnie mentioned Raph.

His brother groaned as the vibrations from the growl went right to his tail. "S...so you should go before Raph-"

"No," Leo interrupted, wrapping his arms around Donnie even tighter. "I don't care about our stupid system. I've been wanting you all day and I can't wait another week."

Despite the situation, Donnie felt himself churr at Leo's words. If he was being honest, he didn't really care for their week-to-week system either. It worked, but there were often times he wished he could be with another brother than the one he was set up with for that particular time.

"I can't wait, either," Donnie admitted, a blush on his cheeks.

His words had an instant effect on the leader who immediately dropped down. Donnie groaned when he felt the hard member press against his backside.

"You got lube in here?"

"Y-yes," Donnie breathed out. "It's in the cabinet over-"

Leo followed his brother's finger then quickly shook his head. "Too far." He flipped Donnie over so his carapace was now flat on the desk. "I'm just gonna have to do it the old fashioned way."

Before Donnie had a chance to respond to that or even offer to go get the lube himself, Leo lowered his head till he was face to face with Donnie's tail.

He carefully brought the appendage to his mouth and suckled gently. Donnie gasped at the feeling and carefully grinded his backside to Leo's mouth, silently begging for more.

The leader chuckled, glad to see his ministrations had clouded over any doubt in Donnie's mind. He released his tail with a quiet pop and moved it out of the way to reveal his brother's puckered anus.

He carefully pressed his lips to it, causing Donnie to buck the air, and then without warning, he plunged his tongue inside.

"Leonardo!" Donnie screamed, his hands clutching the edges of the desk.

Leo chuckled again, holding onto his brother's thigh to keep him in place as he continued to rim him.

At one point, Leo pointed the tip of his tongue and stabbed as far as he could go, hoping to hit that sweet spot deep inside his brother. He must of found it, because Donnie immediately went stiff and his cock popped out of hiding.

Leo got up then, ignoring Donnie's pleas to continue, and wrapped a hand around his brother's now exposed member. He pumped a few times, taking time to run his thumb over the head, collecting the bit of precum that had already accumulated there, then removed his hand.

Again, Donnie whimpered at the loss.

"Don't worry, Don," Leo said, grabbing his own erection and pumping it to fullness. "This will feel a lot better."

The squelcing noise of his precum mingling with Donnie's precum still on his hand sent tremors through Leo's body. Unable to wait any longer, he grabbed hold of Donnie's hips and lined himself up with his hole.

"You ready?"

"Always," Donnie whispered, his eyes half-lidded.

Leo smiled, for a moment forgetting where he was and what they were doing and just focusing on Donnie and his beautiful eyes.

"Leo..." Donnie whimpered.

The leader shook his head to clear his mind and almost immediately sunk into Donnie's warm heat.

He went in with minimal resistance and Leo had to assume that was because Donnie had chosen to bottom for Mikey during most of their week together.

Despite himself, Leo found his thoughts drifting to Raph and wishing it was just as easy for them to submit to each other as it was for their two younger brothers.

"Leo, what the hell?"

 _Speak of the devil,_ Leo thought, as Raph strolled into the lab, Mikey in tow. "This is _my_ week with Donnie!"

"Yeah, well you're just gonna have to wait till I'm done with him," the eldest brother replied, slowing his thrusts.

"What and be stuck with your sloppy seconds?" Raph growled, crossing his arms. "I don't think so."

Leo shrugged. "Well, I'm not moving so..."

The hothead glared at the leader who glared right back.

"Please...don't fight," Donnie begged, terrified Master Splinter would walk in and ban them from each other permanently. Leo purposely rammed into Donnie at an angle, causing the genius to moan in reply, but his eyes remained on Raph.

Despite himself, the red-banded turtle found himself half-choking on the display in front of him. "Fine, then I'll just take _your_ weekly partner for a spin." He turned to his youngest brother. "Mikey, up on desk, next to Donnie. But not too close. I'd rather not have to brush elbows with Leo."

The leader watched curiously as Mikey obeyed, climbing up onto the desk, while Raph crossed the lab to a cupboard and pulled out a used tube of lube.

Raph then positioned himself between Mikey's legs and went right to prepping him.

"Dude, are we actually having a foursome?"

Donnie turned his head to look at his brother, considering his question. It was always one of Mikey's fantasies to be with all his brothers at the same time. To be considered a foursome however, Donnie assumed each member of the party had to be doing something together, and from the looks of it, as Raph purposely pulled Mikey another inch away just to keep a small gap between him and Leo, he didn't think that was going to happen anytime soon.

"I don't think so, Mikey."

Leo slowed his thrusts again, carefully watching Raph prep their youngest brother. It was fascinating watching him work so carefully. On the rare occasions they were actually together, Raph was usually pretty forceful. He didn't realize he had such a gentle side to him.

"Don't you got something better to do than watch me work?" The hothead grumbled when he noticed Leo's eyes trained on him. He noticed his fingers working faster, harder, as soon as he saw Leo was watching him.

Mikey let out a low moan and Raph assumed he was ready. He pulled his fingers out and immediately wrapped them around his member, which had tumbled out not to long ago. He pumped a couple times then forcefully rammed himself into his little brother.

"Nnng, Raph!"

Leo was mesmerized by the scene in front of him. His eyes moving in time with Raph's thrusts. _In, out, in, out._ He hadn't realized he himself had stopped moving until Donnie let out a desperate whimper.

"Leo..." He groaned, slowly moving his hand over his own cock.

His eyes still fixed on Raph and Mikey, Leo pulled almost all the way out, then pressed back into Donnie's heat.

"Oh, shell..." Raph mumbled, watching Donnie squirm under Leo's body. He always loved watching the genius turn to mush as he pounded into him, but watching someone else do it was an even bigger turn on.

In reply, Raph thrust into Mikey, and Leo thrust into Donnie. They began a rhythm, ramming into the younger brothers almost in sync.

"This...is so...hot," Mikey managed between moans, pumping himself in tune with the brothers thrusts.

Donnie smiled and motioned Mikey closer, wrapping his free hand around the back of his head and kissing him.

"No, _that_ is hot," Raph groaned.

With his eyes still on the kissing brothers, Leo grabbed at the top of Raph's plasteron, forcefully pulled him forward, and pressed their lips together, too.

The kiss was intense, nothing but tongue and teeth, and when they finally separated, their thrusts into the other two brothers became just as intense.

Leo grabbed onto Donnie's hips tightly, thrusting in fast and hard as Raph did the same to Mikey.

"Leo, fffuck!" Donnie cried, as Mikey moaned out a few profanities himself.

Almost instantaneously, Donnie and Mikey both came, spilling over their hands and plasterons. Both Leo and Raph moaned as each of their brother's tightened around them.

"Not coming...until you do," Raph grunted, stubbornly.

"Suit yourself," Leo smirked, thrusting in one final time before cumming inside Donnie. Relief washed over Raph's face and he followed right after.

Clearly exhausted, the two older brothers fell forward, their heads resting on their younger brothers sticky plasterons.

Raph turned so he was facing Leo. "This weekly rule thing...sucks. I've...always hated it."

"Same," Mikey spoke up about the same time Donnie said, "Me too."

"Yeah, me too," Leo agreed, still a bit breathless. "Consider...consider the rule...revoked."

Raph widened his eyes. "Really?"

"Yeah," the leader grinned back. "It shouldn't be too hard to share you guys. Especially if we do this..." He waved a hand around, clearly referring to what that had just done together. "As often as possible."

"In that case," Mikey sat up. "Who's up for round two?"

Leo and Raph both grinned at each other and found themselves already growing hard again at the idea. They got up, Leo heading for Mikey, as Raph went for Donnie.

"I call Mikey," Donnie said quickly, pulling his little brother into his arms. "So...it looks like you guys are together."

The two older brothers turned to each other hesitantly.

Somehow, while being pounded the heck into just moments ago, Donnie still managed to realize what had been going on between Raph and Leo. Though, it wasn't really that hard to figure out.

They had just finished up their week together, but it was clear from the sexual tension oozing from them both during the previous activity that they hadn't done anything remotely sexual together during that week.

Now Donnie had some resourceful insight, of course. Raph had recently brought up that he and Leo had only been together, sexually, a few times since they've all started being Intimate with each other. The hotheaded brother admitted he was just as stubborn as Leo when it came to bottoming and that he wished he could be more willing.

Donnie stroked Mikey's arm carefully, watching his two oldest brothers stare at each other, wondering if forcing them together was really such a good idea.

Finally, Leo spoke up. "You can top, Raph."

His eyes boggled. "R-really, Leo?"

"Yes," He admitted, leaning closer. "I want you and I'm tired of pretending I don't due to my own stubbornness."

Raph found himself breathing hard through his mouth. He leaned closer, ready to press his beak to his brother's, when Leo spoke up again.

"Just..." He started, a pleading look in his eyes. "Just promise you'll let _me_ top next time?"

"You got it," Raph husked, tackling Leo to the ground and attacking his lips.

Donnie let out a sigh of relief.

"So," Mikey said, kissing his brother's neck. " _Now_ is it a foursome?"

The genius chuckled and jumped off the desk, offering a hand to his little brother. "Let's go make it one."


End file.
